The hoard of Beçin—non-destructive analysis of the silver coins

We report the results of an analytical investigation on 416 silver-copper coins stemming from the Ottoman Empire (end of 16th and beginning of 17th centuries), using synchrotron micro X-ray fluorescence analysis (SRXRF). In the past, analyses had already been conducted with energy dispersive X-ray fluorescence analysis (EDXRF), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM/EDX) and proton induced X-ray emission spectroscopy (PIXE). With this combination of techniques it was possible to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins.     

Determination of Zn distribution and speciation in basic oxygen furnace sludge by synchrotron radiation induced μ‐XRF and μ‐XANES microspectroscopy

Basic oxygen furnace off gas (BOF OG) sludge is one important type of metallurgical residues in steelmaking industry. The presence of zinc element is one key factor that constrains the practical use of such metallurgical residues. Information about the chemical association of zinc in BOF OG sludge is fundamental for understanding its behavior during the formation and further treatments. In this paper, the spatial distribution and the chemical forms of zinc in accumulated particles of BOF OG sludge have been investigated using synchrotron radiation induced μ‐X‐ray fluorescence and μ‐X‐ray absorption near edge spectroscopy microspectroscopy. Results of μ‐X‐ray fluorescence analysis showed that zinc distributed in two ways. One was shared with iron, and its distribution showed a positive correlation with that of iron. The other was accumulated in some well‐defined hot spots with high amount and its distribution showed negative correlation with that of iron. And results of μ‐X‐ray absorption near edge spectroscopy microspectroscopy indicated that ZnFe₂O₄ was the main constituent in some well‐defined hot spots, whereas in other cases, zinc was mainly in the form of zinc carbonate. Copyright © 2013 John Wiley & Sons, Ltd.     

Determination of the provenance of medieval silver coins: potential and limitations of x‐ray analysis using photons,electrons or protons

One hundred and fifty seven ‘Tiroler Kreuzer’, a medieval currency from the county of Tyrol/Austria, were analysed in order to determine their place of mintage. The silver coins were produced during the 15th century in the mints of Merano (South Tyrol) and Hall (North Tyrol) but they have no marks or punches which would allow a clear distinction. Energy‐dispersive x‐ray fluorescence analysis (EDXRF) was applied without sampling in order to determine the silver contents and also minor (Cu, Pb, Bi) and trace elements (Fe, Au, Hg, Ni). Owing to corrosion processes, which changed the chemical composition of the surfaces of the coins, investigations of cross‐sections were necessary using energy‐dispersive x‐ray microanalysis in a scanning electron microscope (SEM/EDX) to determine the stage of corrosion and the Ag concentration of the core of the coins. The results showed differences of up to 50% between the composition of the core and the surface. Finally, proton‐induced x‐ray emission (PIXE) at an external proton beam was applied, in order to detect also Ni, an element which could not be measured by either EDXRF or SEM/EDX in the ppm range. The data show a clear difference in the Ni content between the coins from Merano (～0.1% Ni) and Hall (～0.01% Ni). Copyright © 2003 John Wiley & Sons, Ltd.     

Micro‐Raman innovative methodology to identify Ag–Cu mixed sulphides as tarnishing corrosion products

Mixed Cu–Ag alloys with different compositions have been produced and subjected to an accelerated sulphidation process which causes the development of a mixed sulphide‐rich corroded film on their surface. It was called tarnishing, that is, the formation of a blue‐brownish patina when Cu–Ag alloys are exposed in a sulfur‐containing atmosphere. The structures of the pristine alloys have been determined by the combined analytical techniques as scanning electron microscopy energy dispersive X‐ray microanalysis and X‐ray diffraction. The experimental conclusions confirmed the occurrence of micro phase separation with the formation of different dendritic domains of about 10 µm in width. The sulphidized samples were firstly investigated by optical microscopy and X‐ray diffraction in order to verify the homogeneity of the patina and to identify the different AgCuS phases appearing on the alloy surfaces. It was observed that, despite the inherent micro‐heterogeneity of the alloys, the sulphide layer was throughout uniform in composition at the micro‐scale. The complex scenario of the relative stability of all the various mixed sulphides involved was then explored by micro‐Raman spectroscopy (μ‐RS), pointing out that the Cu‐for‐Ag substitution in the crystal lattice of the mixed Ag–Cu sulphides caused a monotonous blue shift of the vibrational wavenumbers in Raman spectra. This study has unveiled microscopic details of the tarnishing process, furnishing an innovative, cheap and non‐destructive methodology based on μ‐Raman spectroscopy for the evaluation of the silver‐copper artefacts via the compositions of their corroded products. Copyright © 2016 John Wiley & Sons, Ltd.     

Fensterbierscheiben in the Pena National Palace collection – chemical and iconographic relations

The stained‐glass collection from the Pena National Palace (Sintra, Portugal) includes around 130 ‘rural panels’, also known as Fensterbierscheiben, that were produced between the 16th and 19th centuries. The aim of this investigation is to characterise the glass composition of this collection of Fensterbierscheiben and relate it with the iconographic research made on these panels, in order to establish possible provenance of production. This is the first study on Fensterbierscheiben, where the chemical information of the glass is considered and related with historical information. The micro‐energy dispersive X‐ray fluorescence allowed performing non‐invasive analysis, mostly performed in situ. Micro‐particle‐induced X‐ray emission analysis was performed on the cross section of a small group of fragmented panels for obtaining quantitative chemical composition of the glass. Through the analysis of the colourless glass, and the comparison of micro‐energy dispersive X‐ray fluorescence and micro‐particle‐induced X‐ray emission data, it was concluded that the majority of the panes have a high lime low alkali glass composition. Furthermore, the Fensterbierscheiben panes form a cohesive group in terms of composition, suggesting that they were all manufactured with raw materials from the same region. This study also allowed one to observe the chronological evolution in terms of treatments applied to the used raw materials. Copyright © 2016 John Wiley & Sons, Ltd.     

Toward sub‐micro‐XRF working at nanometer range using capillary optics

Capillary optics are used for X‐ray fluorescence micro‐analysis using the Cu Kα line provided by a rotating anode. The excitation beam is focused using a polycapillary lens on a Co–Ti sample. Cylindrical glass capillaries of various diameters are fitted to the X‐ray detector (Energy Dispersive X‐Ray (EDX) analyzer) and displaced along the irradiated zone of the sample. The fluorescence is studied as a function of capillary position. Good agreement is found between experimental and calculated lateral widths of the fluorescence collection, taken into account the cylindrical capillary critical angles relevant in the experiment. The influence of the cylindrical capillary diameter on the signal level detected is studied to estimate the possibility of lateral resolution increase of X‐ray fluorescence technique both in‐lab and in synchrotron environment. Copyright © 2013 John Wiley & Sons, Ltd.     

Comparative study of multilayers used in monochromators for synchrotron‐based coherent hard X‐ray imaging

A systematic study is presented in which multilayers of different composition (W/Si, Mo/Si, Pd/B₄C), periodicity (from 2.5 to 5.5 nm) and number of layers have been characterized. In particular, the intrinsic quality (roughness and reflectivity) as well as the performance (homogeneity and coherence of the outgoing beam) as a monochromator for synchrotron radiation hard X‐ray micro‐imaging are investigated. The results indicate that the material composition is the dominating factor for the performance. By helping scientists and engineers specify the design parameters of multilayer monochromators, these results can contribute to a better exploitation of the advantages of multilayer monochromators over crystal‐based devices; i.e. larger spectral bandwidth and high photon flux density, which are particularly useful for synchrotron‐based micro‐radiography and ‐tomography.     

Depth profiling of dopants implanted in Si using the synchrotron radiation based high‐resolution grazing emission technique

We report on the surface‐sensitive grazing emission X‐ray fluorescence technique combined with synchrotron radiation excitation and high‐resolution detection to realize depth‐profile measurements of Al‐implanted Si wafers. The principles of grazing emission measurements as well as the benefits offered by synchrotron sources and wavelength‐dispersive detection setups are presented. It is shown that the depth distribution of implanted ions can be extracted from the dependence of the X‐ray fluorescence intensity on the grazing emission angle with nanometer‐scale precision provided that an analytical function describing the shape of the depth distribution is assumed beforehand. If no a priori assumption is made, except a bell shaped form for the dopant distribution, the profile derived from the measured angular distribution is found to reproduce quite satisfactorily the depth distribution of the implanted ions. Copyright © 2012 John Wiley & Sons, Ltd.     

A confocal set‐up for micro‐XRF and XAFS experiments using diamond‐anvil cells

A confocal set‐up is presented that improves micro‐XRF and XAFS experiments with high‐pressure diamond‐anvil cells (DACs). In this experiment a probing volume is defined by the focus of the incoming synchrotron radiation beam and that of a polycapillary X‐ray half‐lens with a very long working distance, which is placed in front of the fluorescence detector. This set‐up enhances the quality of the fluorescence and XAFS spectra, and thus the sensitivity for detecting elements at low concentrations. It efficiently suppresses signal from outside the sample chamber, which stems from elastic and inelastic scattering of the incoming beam by the diamond anvils as well as from excitation of fluorescence from the body of the DAC.     

Investigation of nanoscale element distributions at surfaces with grazing incidence X‐ray spectroscopy techniques – an instrumentation study

Grazing incidence X‐ray methods are well‐established in the characterization of nanostructures at interfaces and surfaces. The purpose of the experiments reviewed in this work is the comparative characterization of different instrumentation concepts for grazing incidence X‐ray fluorescence analyses. Fluorescence scans recorded with a total reflection X‐ray fluorescence spectrometer featuring a variable angle of incidence are compared with data obtained with synchrotron radiation. The conclusions to the element distribution profiles, which are drawn from fluorescence scans carried out with the respective instrument, are compared. This way, the suitability of the total reflection X‐ray fluorescence spectrometer to complement synchrotron radiation facilities and the possibility to transfer surface and interface analyses from the synchrotron to the laboratory are assessed. The structures investigated include an Au on Si surfaces in the form of layers and particles, submicrometer‐sized droplets, a liquid film, and ions implanted into a Si wafer. Copyright © 2014 John Wiley & Sons, Ltd.     

A simple calibration procedure of polycapillary based portable micro‐XRF spectrometers for reliable quantitative analysis of cultural heritage materials

Portable micro‐X‐ray fluorescence (micro‐XRF) spectrometers mostly utilize a polycapillary X‐ray lens along the excitation channel to collect, propagate and focus down to few tens of micrometers the X‐ray tube radiation. However, the polycapillary X‐ray lens increases the complexity of the quantification of micro‐XRF data because its transmission efficiency is strongly dependent on the lens specifications and the propagated X‐ray energy. This feature results to a significant and not easily predicted modification of the energy distribution of the primary X‐ray tube spectrum. In the present work, we propose a simple calibration procedure of the X‐ray lens transmission efficiency based on the fundamental parameters approach in XRF analysis. This analytical methodology is best suited for compact commercial and portable micro‐XRF spectrometers. The developed calibration procedure is validated through the quantitative analysis of a broad range of samples with archeological relevance such as glasses, historical copper alloys, silver and gold alloys offering an overall accuracy of less than 10%–15%. Copyright © 2015 John Wiley & Sons, Ltd.     

Literature trends in x‐ray emission spectrometry in the period 1990–2000–a review

A quantitative overview is given of the role that x‐ray emission analysis methods, in their various forms, play in the literature for the period from January 1990 to the end of December 2000. The major sources of information were computerized searches through Chemical Abstracts and Web of Science and, specifically for 1998, a manual search through Analytical Abstracts. Areas that are covered in this review pertain to the recent trends in x‐ray emission spectrometry in general and in some specific techniques such as x‐ray fluorescence analysis, synchrotron radiation‐induced and particle‐induced x‐ray emission, total‐reflection and micro‐x‐ray fluorescence analysis. A brief outline of recent developments in the specific fields is given, with emphasis on the various excitation and detection modes, on different application areas and on relative contributions of different countries and languages to the x‐ray emission spectrometry literature. It appears that environmental monitoring and research continue to be particularly important publication fields for x‐ray spectrometry. Copyright © 2003 John Wiley & Sons, Ltd.     

Fluorescence imaging of reactive oxygen species by confocal laser scanning microscopy for track analysis of synchrotron X‐ray photoelectric nanoradiator dose: X‐ray pump–optical probe

Bursts of emissions of low‐energy electrons, including interatomic Coulomb decay electrons and Auger electrons (0–1000 eV), as well as X‐ray fluorescence produced by irradiation of large‐Z element nanoparticles by either X‐ray photons or high‐energy ion beams, is referred to as the nanoradiator effect. In therapeutic applications, this effect can damage pathological tissues that selectively take up the nanoparticles. Herein, a new nanoradiator dosimetry method is presented that uses probes for reactive oxygen species (ROS) incorporated into three‐dimensional gels, on which macrophages containing iron oxide nanoparticles (IONs) are attached. This method, together with site‐specific irradiation of the intracellular nanoparticles from a microbeam of polychromatic synchrotron X‐rays (5–14 keV), measures the range and distribution of OH radicals produced by X‐ray emission or superoxide anions () produced by low‐energy electrons. The measurements are based on confocal laser scanning of the fluorescence of the hydroxyl radical probe 2‐[6‐(4′‐amino)phenoxy‐3H‐xanthen‐3‐on‐9‐yl] benzoic acid (APF) or the superoxide probe hydroethidine‐dihydroethidium (DHE) that was oxidized by each ROS, enabling tracking of the radiation dose emitted by the nanoradiator. In the range 70 µm below the irradiated cell, radicals derived mostly from either incident X‐ray or X‐ray fluorescence of ION nanoradiators are distributed along the line of depth direction in ROS gel. In contrast, derived from secondary electron or low‐energy electron emission by ION nanoradiators are scattered over the ROS gel. ROS fluorescence due to the ION nanoradiators was observed continuously to a depth of 1.5 mm for both oxidized APF and oxidized DHE with relatively large intensity compared with the fluorescence caused by the ROS produced solely by incident primary X‐rays, which was limited to a depth of 600 µm, suggesting dose enhancement as well as more penetration by nanoradiators. In conclusion, the combined use of a synchrotron X‐ray microbeam‐irradiated three‐dimensional ROS gel and confocal laser scanning fluorescence microscopy provides a simple dosimetry method for track analysis of X‐ray photoelectric nanoradiator radiation, suggesting extensive cellular damage with dose‐enhancement beyond a single cell containing IONs.     

Status of the hard X‐ray microprobe beamline ID22 of the European Synchrotron Radiation Facility

The ESRF synchrotron beamline ID22, dedicated to hard X‐ray microanalysis and consisting of the combination of X‐ray fluorescence, X‐ray absorption spectroscopy, diffraction and 2D/3D X‐ray imaging techniques, is one of the most versatile instruments in hard X‐ray microscopy science. This paper describes the present beamline characteristics, recent technical developments, as well as a few scientific examples from recent years of the beamline operation. The upgrade plans to adapt the beamline to the growing needs of the user community are briefly discussed.     

Dimensional characterization of selected elements in airborne PM10 samples using μ‐SRXRF

Micro synchrotron radiation X‐ray fluorescence (μ‐SRXRF) is a powerful spectroscopy technique that uses synchrotron radiation to induce X‐ray fluorescence in samples and provides exhaustive information on the micron and submicron scale. Among the major advantages of μ‐SRXRF spectroscopy are its nondestructive nature and that samples can usually be analyzed without pretreatment. At the ESRF (Grenoble, France) ID‐21 beamline, we examined PM₁₀ samples collected at two sites in the Province of Trieste, Italy, in order to determine possible correlations among some low‐ to mid‐Z elements (S, Cl, K, Ca, Ti, V, Cr, Mn, and Fe), as well as investigated the possibility of using synchrotron radiation imaging techniques as a way to examine the granulometry of PM₁₀ particles containing the various chemical elements. A consistent significant correlation between Ca and S has been found, which, coupled with the data obtained in a related study, indicates that a major part of the sulfate is present as CaSO₄. Granulometry measurement via imaging techniques has shown that some elements such as Fe, Ca, and S are more amenable to this type of analysis than others. Additionally, the spatial homogeneity of a PM_2.5 certified reference material (NIST SRM‐2783) has been investigated by analyzing four adjacent areas on the certified sample (total area 1 mm²). The certified reference material has shown a percentage relative standard deviation less than 7% for Al, Si, P, S, Cl, K, Ca, V, Cr, and Fe, and close to 17% for Ti and Mn. Copyright © 2011 John Wiley & Sons, Ltd.     

Synchrotron XANES and ED‐XRF analyses of fine‐paste ware from 13th to 14th century maritime Southeast Asia

The combination of energy dispersive X‐ray fluorescence (ED‐XRF) and synchrotron X‐ray absorption near‐edge structure (XANES) provides the detailed composition of fine‐paste ware (FPW) kendis, dated back to 13th–14th century maritime Southeast Asia. Sources of clay and production sites were classified according to Al₂O₃, SiO₂, α‐Fe₂O₃ and γ‐Fe₂O₃ as well as trace elements. The similarities based on these components provided another evidence of a trade route between Kota Cina in North Sumatra of Indonesia and Kok Moh on Satingphra Peninsula, a well‐known production area in present‐day Thailand. In additions, the uniquely large contribution of α‐Fe₂O₃ in XANES spectra suggests that Nakhon Si Thammarat province of Thailand could also be one of FPW production areas in maritime Southeast Asia. Copyright © 2017 John Wiley & Sons, Ltd.     

Synchrotron‐based spectroscopy of X‐ray channeling through hollow capillary microchannels inside glass plates

Here, soft X‐ray synchrotron radiation transmitted through microchannel plates is studied experimentally. Fine structures of reflection and XANES Si L‐edge spectra detected on the exit of silicon glass microcapillary structures under conditions of total X‐ray reflection are presented and analyzed. The phenomenon of the interaction of channeling radiation with unoccupied electronic states and propagation of X‐ray fluorescence excited in the microchannels is revealed. Investigations of the interaction of monochromatic radiation with the inner‐shell capillary surface and propagation of fluorescence radiation through hollow glass capillary waveguides contribute to the development of novel X‐ray focusing devices in the future.     

X‐ray beam‐position feedback system with easy‐to‐use beam‐position monitor

X‐ray beam‐position stability is indispensable in cutting‐edge experiments using synchrotron radiation. Here, for the first time, a beam‐position feedback system is presented that utilizes an easy‐to‐use X‐ray beam‐position monitor incorporating a diamond‐fluorescence screen. The acceptable range of the monitor is above 500 µm and the feedback system maintains the beam position within 3 µm. In addition to being inexpensive, the system has two key advantages: it works without a scale factor for position calibration, and it has no dependence on X‐ray energy, X‐ray intensity, beam size or beam shape.     

Fast‐scanning high‐flux microprobe for biological X‐ray fluorescence microscopy and microXAS

There is a growing interest in the biomedical community in obtaining information concerning the distribution and local chemical environment of metals in tissues and cells. Recently, biological X‐ray fluorescence microscopy (XFM) has emerged as the tool of choice to address these questions. A fast‐scanning high‐flux X‐ray microprobe, built around a recently commissioned pair of 200 mm‐long Rh‐coated silicon Kirkpatrick–Baez mirrors, has been constructed at BioCAT beamline 18ID at the Advanced Photon Source. The new optical system delivers a flux of 1.3 × 10¹² photons s^?1 into a minimum focal spot size of ～3–5 µm FWHM. A set of Si drift detectors and bent Laue crystal analyzers may be used in combination with standard ionization chambers for X‐ray fluorescence measurements. BioCAT's scanning software allows fast continuous scans to be performed while acquiring and storing full multichannel analyzer spectra per pixel on‐the‐fly with minimal overhead time (<20 ms per pixel). Together, the high‐flux X‐ray microbeam and the rapid‐scanning capabilities of the BioCAT beamline allow the collection of XFM and micro X‐ray absorption spectroscopy (microXAS) measurements from as many as 48 tissue sections per day. This paper reports the commissioning results of the new instrument with representative XFM and microXAS results from tissue samples.     

Valence‐to‐core X‐ray emission spectroscopy of titanium compounds using energy dispersive detectors

X‐ray emission spectroscopy (XES) of transition metal compounds is a powerful tool for investigating the spin and oxidation state of the metal centers. Valence‐to‐core (vtc) XES is of special interest, as it contains information on the ligand nature, hybridization, and protonation. To date, most vtc‐XES studies have been performed with high‐brightness sources, such as synchrotrons, due to the weak fluorescence lines from vtc transitions. Here, we present a systematic study of the vtc‐XES for different titanium compounds in a laboratory setting using an X‐ray tube source and energy dispersive microcalorimeter sensors. With a full‐width at half‐maximum energy resolution of approximately 4 eV at the Ti Kβ lines, we measure the XES features of different titanium compounds and compare our results for the vtc line shapes and energies to previously published and newly acquired synchrotron data as well as to new theoretical calculations. Finally, we report simulations of the feasibility of performing time‐resolved vtc‐XES studies with a laser‐based plasma source in a laboratory setting. Our results show that microcalorimeter sensors can already perform high‐quality measurements of vtc‐XES features in a laboratory setting under static conditions and that dynamic measurements will be possible in the future after reasonable technological developments.